A limitation of other diagnostic systems for battery modules is that each diagnostic system typically opens a contactor associated with the battery module based on a single diagnostic flag which is set to a fault value based on a single signal at a single hardware device. Thus, if the single hardware device is malfunctioning, a desired opening operation of the contactor may not occur.
The inventive diagnostic system provides a technical effect of performing a first diagnostic test on a battery system utilizing first and second diagnostic indicator flags determined utilizing first and second hardware devices (e.g., analog-to-digital converter in a first microcontroller, and a fault line coupled between first and second microcontrollers), respectively. The inventive diagnostic system can open a contactor based on the first and second diagnostic indicator flags. Further, the inventive diagnostic system performs a second diagnostic test on the battery system utilizing third and fourth diagnostic indicator flags determined from third and fourth hardware devices (e.g., voltage comparators in a first microcontroller, and a serial bus), respectively. Further, the inventive diagnostic system can open a contactor based on the third and fourth diagnostic indicator flags.